Funnel of flexible stethoscope for mediate auscultation



Dec. 24, 1968 SHLYAKHTER ET AL 3,417,838

FUNNEL OF FLEXIBLE STETHOSCOPE FOR MEDIATE AUSCULTATION Filed Dec. 14,1966 United States Patent 3,417,838 FUNNEL 0F FLEXIBLE STETHOSCOPE FORMEDIATE AUSCULTATION Isaak Abramovich Shlyakhter, Vasilievsky ostrov, 2linia, 43, kv. I4, Leningrad, U.S.S.R.; Boris Nikolaevich Krupin, p/oMendeleevo, 29, kv. 34, Moskovskaya oblast, U.S.S.R.; and RavilIbragimovich Gismatullin, Lesnoi prospekt, 4, kv. 42, Leningrad,U.S.S.R.

Filed Dec. 14, 1966, Ser. No. 601,593 1 Claim. (Cl. 181-24) ABSTRACT OFTHE DISCLOSURE A stethoscope funnel having a circular housing with anopen cavity of circular extent eccentrically disposed in the housing anddefining an upper rim of variable thickness bounding the cavity. A soundtransfer duct opens into the cavity and is positioned at an acute anglewith respect to the rim of the housing at the location of smallest widthof the housing.

This invention relates to flexible stethoscopes for performing mediateauscultation and more particularly to the funnels of said stethoscopes.

It is known to employ flexible stethoscopes for mediate auscultationwherein the reception space of the funnels communicates with a soundtransfer duct through sound branch tubes. The axis of the aforesaidsound transfer duct is essentially parallel to the plane of contact ofsaid funnel with the body of the patient being auscultated while thecontact surface has an annular shape constituted by two concentriccircumferences. The funnels of the character set forth hereinabove,however, fail to provide the necessary level of transmission of soundenergy from the reception space, which adversely affects the acousticqualities of said funnels.

It is an object of the present invention to eliminate the disadvantagesof the funnels of the stethoscopes hitherto used.

A further and more specific object of the invention is to provide afunnel of such a design that it is possible to attain the maximum levelof transmission of sound energy from a reception space to a soundtransfer duct, thereby improving the acoustic susceptibility of saidfunnel while detecting pathologic symptoms in the sound signal beingheard.

In the accomplishment of this and other objects of the invention, it isprovided in the invention that the axis of the sound transfer duct makesan acute angle with the plane of the annular surface which contacts thebody of the patient being auscultated. Apart from this, the said annularsurface is confined within eccentric circumferences such that theannular surface has its greatest width on the side opposite the side onwhich the sound transfer duct is connected to the annular surface.

An embodiment of the present invention will be described hereinbelowwith reference to the accompanying drawings, wherein:

FIG. 1 is a diagrammatic side sectional view of the funnel according tothe invention taken on lines IIII;

FIlgIG. 2 is a plan view of the funnel as illustrated in The funnel of aflexible stethoscope of the present invention comprises a circularhousing H which has an annular-shaped surface or rim 1 which contactsthe body of the patient being auscultated, said surface 1 being disposedin a plane P which makes an acute angle a with the axis of a soundtransfer duct 2, said duct being connected to a reception space orcavity 3 provided in housing H.

The reception space is eccentrically located in housing H andannular-shaped surface 1 has its greatest Width on the side oppositethat at which the sound transfer duct 2 enters the cavity 3. Thus asshown in FIGS. 1 and 2 the maximum width W is diametrically oppositeduct 2 whereas the minimum width W, is closest to the duct.

The boundary of the space 3 in plane P is designated by numeral 4 and iscircular as shown in FIG. 2, while the boundary of the housing H inplane P is also circular and designated by numeral 5. The axis of duct 2lies in a plane which passes diametrically through circular boundaries 4and 5.

The funnel of the present invention features high acoustic propertiesand an advanced acoustic susceptibility thus enabling pathologicsymptoms in the sounds inherent in a human organism to be revealed andrecognized With a high degree of accuracy, this due to the fact that thedesign of the funnel embodying the present invention provides for thehighest concentration of the sonic waves in close proximity to the soundtransfer duct.

We claim:

1. A stethoscope funnel comprising a cylindrical housing having an upperand lower surface, the lower surface being perpendicular to the axis ofthe housing, the upper surface being inclined at an acute angle withrespect to said lower surface, said housing having a circular soundcavity in said upper surface which is offset therein to form a rim ofvarying Width surrounding the said cavity, said rim having a minimumwidth at the point of greatest depth of the housing and a maximum widthat the point of minimum depth of the housing, and a duct in said housingat the point-of maximum depth thereof, said duct extending parallel tosaid lower surface and opening into said cavity in the region of minimumwidth of the rim and remote from the region of maximum width of the rim.

References Cited UNITED STATES PATENTS 677,172 6/ 1901 BoWles 181-24910,854 1/1909 Pilling 181-24 1,853,951 4/1932 Zala 18124 2,445,917 7/1948 Mallory 181-24 3,276,536 10/1966 Littmann l8124 3,389,667 9/1967Speelman 181-24 FOREIGN PATENTS 1,164,669 5/ 8 France. 1,208,208 9/1959France.

STEPHEN J. TOMSKY, Primary Examiner.

